1. Field of the Invention
This invention relates to apparatus which provides for a reduction of interior noise in high speed tracked vehicles, and more particularly to reduction of interior noise resulting from contact between track idler wheels and track shoes.
2. Description of the Prior Art
Noise production within a tracked vehicle results when vibration is generated, transmitted through the vehicle structure, radiated to the interior and amplified by resonant conditions. A typical track driven vehicle is structurally complex and has many sources of noise generation which are transmitted, radiated and resonated to produce an interior noise level. Reduction of the noise level by reducing the mass of the tracks or by increasing the diameter of idler wheels for the tracks has been implemented in the past. Nonetheless, relatively high interior noise levels have continued to exist due in part to structural vibrations resulting from track shoe impact on the track idler wheels. The impact is caused by the absorption of track shoe momentum directed normal to the track idler wheel rims. The vibration excitation results from the relatively instantaneous absorption of the track shoe momentum due to a relatively high stiffness of the track shoe because of the large area of contact between the idler wheel rim and elastomeric track shoe inserts which are positioned to contact the idler rims.